1. Will the server work if the machine is already VNC?
It works on different ports so the two can co-exist.
2. Can I use the internet connection if both systems are behind the same NAT? I was trying this for testing. (Two computer on the same router.) Is this possible besides using the direct connect?
You'll need to set up port forwarding for either the repeater, for the direct connection or use the public repeater. Have you tried [topic=9663]"Zero Configuration" PcHelpWare_viewer Setup[/topic]? It shows setup using a public repeater so you wouldn't need to do anything with your router.